JP6202422B2 - Method for producing polymer electrolyte - Google Patents

Description

The present invention relates to a method for producing a polymer electrolyte and a polymer electrolyte obtained by the method.

Polymer electrolytes containing proton conductive substituents are used as raw materials for electrochemical devices such as fuel cells, humidity sensors, gas sensors, and electrochromic display devices. Among these, fuel cells are expected as one of the pillars of new energy technology. Solid polymer fuel cells that use polymer electrolytes with proton-conducting substituents can be operated at low temperatures and can be reduced in size, weight, mobile vehicles such as automobiles, household cogeneration systems, and civilian use. Application to small portable devices is under consideration. For example, a direct methanol fuel cell (DMFC) that uses methanol directly as fuel has features such as a simple structure, ease of fuel supply and maintenance, and high energy density. Application to small portable devices for private use such as telephones and notebook computers is expected. A polymer electrolyte fuel cell (PEFC) is suitable as an electric vehicle or a household power source.

These PEFCs and DMFCs are usually operated at a temperature of 80 ° C. or lower. However, in order to improve performance, the PEFC and DMFC can be operated at 120 ° C. or higher and in a low humidified condition from the viewpoint of catalytic activity, catalyst poisoning, and waste heat utilization. It has been demanded. Therefore, electrolytes used for PEFC and DMFC are required to maintain membrane strength even at high temperatures and to exhibit high proton conductivity even under low humidification conditions. However, fluorine-based electrolyte membranes that are currently mainstream (membranes such as Nafion, Aciplex, and Flemion, which are perfluoroalkyl sulfonic acid polymers) have problems in heat resistance, such as a decrease in membrane strength at 100 ° C. or higher.

In order to solve such problems, many polymer electrolytes using aromatic compounds have been studied. For example, a polyarylene polymer electrolyte obtained by polymerizing a monomer having a sulfonate ester and an oligomer for a hydrophobic portion is known. It has been. However, since these electrolytes are prepared using a monomer or oligomer having a leaving group and a transition metal, the polymer after polymerization contains a leaving group, a metal-derived impurity, and a ligand of the metal complex used in the reaction. May remain. Therefore, it is known that when a polymer electrolyte that is not sufficiently purified is used inside a fuel cell, it may cause deterioration of a catalyst or a polymer electrolyte membrane. For example, when metal remains in the film, it becomes a radical generation source. In addition, it is known that peroxides are generated in the system, which causes deterioration of the film. When the ligand or halogen ion of the metal complex remains, there is an influence such as catalyst poisoning that lowers the activity of the catalyst and a voltage drop. For example, when a halogen anion is present in the cathode catalyst layer, the catalyst loses its activity because it is chemically bonded to the catalyst by electric potential. As a ligand of a metal complex, there is a compound having an unsaturated bond as a strong interaction with a catalyst.

Therefore, for example, in Patent Document 1, the polymer solution after polymerization is put into a poor solvent for polyarylene having a sulfonic acid group, and the polyarylene having a sulfonic acid group is precipitated and recovered, and each metal impurity is collected. The method of removing to 100 ppm or less is described. In this method, the polyarylene having a sulfonic acid group once precipitated needs to be dissolved and precipitated again, and the operation is complicated, and the washing is performed only with an aqueous solvent. Patent Document 2 describes a purification method in which a polymer electrolyte containing metal impurities is dissolved in a solvent containing sulfuric acid, and an electrolyte having a reduced impurity content is taken out. However, an aromatic ring that is easily sulfonated has a high possibility of reacting with sulfuric acid, so that not only the polyelectrolyte that can be used is limited, but also this method is only an aqueous washing operation. For example, Patent Document 3 describes an example in which the content of a halogen element in a hydrocarbon-based electrolyte is reduced to 1 × 10 ⁻⁶ mol / g or less by a cleaning operation using a Soxhlet extractor.

As described above, the conventional purification method is limited to the purification method for metal impurities and halogen impurities, and other methods for removing molecules that cause deterioration of the catalyst and electrode are not studied. In addition, a compound having an unsaturated bond has a solubility different from that of a metal or a halogen element, and thus may not be sufficiently removed by a conventional purification method.

For example, when a transition metal complex such as bis (1,5-cyclooctadiene) nickel (0) is used in preparing a polymer electrolyte, the conventional purification method does not sufficiently remove halogen elements and metal impurities. In addition, there are cases where coordinating organic molecules remain. When the present inventors analyzed the phenomenon of voltage drop during fuel cell power generation when these impurities remain, in addition to the impurities used in the reaction, organic molecules used as ligands in the polymer electrolyte Was modified to produce oligomers having a number average molecular weight of 10,000 or less, which became catalyst poisons for the fuel cell catalyst and lowered the voltage during power generation.

JP 2005-239833 A JP 2009-187933 A JP 2009-43457 A

An object of the present invention is to provide a method for purifying a polymer electrolyte, which reduces the content of a compound containing an oligomer having a number average molecular weight of 10,000 or less, contained in the polymer electrolyte.

As a result of further intensive studies, the inventors of the present invention have found that the catalyst for a fuel cell contained in the polymer electrolyte is washed with at least two types of polymer electrolyte poor solvents. In addition to reducing oligomers with a number average molecular weight of 10,000 or less that interact with each other, other impurities can also be efficiently removed, and a polymer electrolyte that suppresses voltage drop has been successfully obtained, thereby completing the present invention. It came.

That is, this invention relates to the manufacturing method of a polymer electrolyte including the process of wash | cleaning the polymer electrolyte containing an oligomer with a number average molecular weight 10,000 or less using the poor solvent of at least 2 types of polymer electrolyte.

As the poor solvent for the polymer electrolyte, it is preferable to use a protic solvent and an aprotic solvent.

The protic solvent is preferably an alcohol solvent.

The aprotic solvent is preferably a halogen solvent.

The oligomer having a number average molecular weight of 10,000 or less is preferably a hydrocarbon compound substituted with a halogen element and / or a hydrocarbon compound containing an unsaturated bond.

（式中、Ａｒはベンゼン環、ナフタレン環、またはそれらの環を形成する炭素がヘテロ原子へと置換されたものを示し、Ｘは水素または陽イオンを示す。ａおよびｂは、それぞれ０〜４の整数である。また、ａ＋ｂは１以上である。ｍは１以上の整数を示し、ｎは０以上の整数を示す。）
で示される構造を有することが好ましい。 The polymer electrolyte is at least the following formula (1)

(In the formula, Ar represents a benzene ring, a naphthalene ring, or a carbon in which those rings are substituted with a hetero atom, X represents hydrogen or a cation. In addition, a + b is 1 or more, m is an integer of 1 or more, and n is an integer of 0 or more.)
It is preferable to have the structure shown by these.

（式中、Ａｒはベンゼン環、ナフタレン環、またはそれらの環を形成する炭素がヘテロ原子へと置換されたものを示す。ｍは１以上の整数を示し、ｎは０以上の整数を示す。Ｙ^１はＳＯ_２、Ｃ（ＣＨ_３）_２、またはＣ（ＣＦ_３）_２であり、Ｚは直接結合、酸素、または硫黄を示す。）および／または下記式（３） The polymer electrolyte is represented by the following formula (2)

(In the formula, Ar represents a benzene ring, a naphthalene ring, or a carbon in which those rings are substituted with a hetero atom. M represents an integer of 1 or more, and n represents an integer of 0 or more. Y ¹ is SO ₂ , C (CH ₃ ) ₂ , or C (CF ₃ ) ₂ , Z represents a direct bond, oxygen, or sulfur.) And / or the following formula (3)

（式中、Ａｒ、ｍ、ｎは前記式（２）と同様である。Ｙ^２はＣＯ、ＳＯ_２、Ｃ（ＣＨ_３）_２、またはＣ（ＣＦ_３）_２であり、Ｙ^１とは異なる。Ｚは直接結合、酸素、または硫黄を示す。）
で示される構造を有し、式（２）で示される構造成分Ａモルに対し、式（３）で示される構造成分Ｂモルが、Ｂ／（Ａ＋Ｂ）が０〜０．９５を満たすことが好ましい。

(In the formula, Ar, m, and n are the same as those in the formula (2). Y ² is CO, SO ₂ , C (CH ₃ ) ₂ , or C (CF ₃ ) ₂ , and is different from Y ^1. Z represents a direct bond, oxygen or sulfur.)
The structural component B represented by the formula (3) has a structure represented by the formula (2), and the B / (A + B) satisfies 0 to 0.95 with respect to the structural component A represented by the formula (2). preferable.

The present invention also relates to a polymer electrolyte obtained by the production method of the present invention.

According to the method for producing a polymer electrolyte of the present invention, it is possible to obtain a polymer electrolyte in which the voltage drop during power generation of the fuel cell is suppressed.

It is the figure which showed the voltage maintenance factor of the electric power generation test which concerns on Example 1. FIG.

An embodiment of the present invention will be described as follows. It should be noted that the present invention is not limited to the following description.

(1. Production method of polymer electrolyte)
The production method of the present invention includes a step of washing a polymer electrolyte containing an oligomer having a number average molecular weight of 10,000 or less using a poor solvent for at least two kinds of polymer electrolytes.

The poor solvent used here is a poor solvent for the polymer, and may be any solvent that dissolves the monomer or oligomer used in the polymerization or the metal compound-containing material, and examples thereof include a protic solvent and an aprotic solvent. Examples of the protic solvent include alcohol solvents. Examples of the aprotic solvent include hydrocarbon solvents, halogen solvents, ether solvents and the like. Examples of the hydrocarbon solvent include benzene, toluene, n-hexane, methylcyclohexane and the like. Examples of alcohol solvents include methanol, ethanol isopropyl alcohol, butanol and the like. Examples of the halogen solvent include dichloromethane, chloroform, 1,1,1-trichloroethane and the like. Examples of the ether solvent include diethyl ether, tetrahydrofuran, 1,4-dioxane, methyl tert-butyl ether, dimethoxyethane, ethylene glycol dimethyl ether and the like. These solvents may be used alone or in combination of two or more. Among them, alcohol solvents such as methanol, ethanol and isopropyl alcohol are preferably selected as the protic solvent, and halogen solvents such as dichloromethane and chloroform are preferably used as the aprotic solvent in view of high impurity solubility. In particular, as the two poor solvents, one of the first poor solvent and the second poor solvent is a protic solvent, and the other is preferably an aprotic solvent in view of the purification effect.

In washing, a solvent in which the first poor solvent and the second poor solvent are mixed may be used for washing or separately. It is preferable to wash each poor solvent, that is, separately from the point of excellent washing efficiency.

What is necessary is just to set the quantity of a 1st poor solvent suitably, specifically 0.1 weight part or more is preferable with respect to 1 weight part of preparation amounts of a polymer, and 1 weight part or more is more preferable. Moreover, 1000 weight part or less is preferable, 500 weight part or less is more preferable, and 100 weight part or less is further more preferable. If the amount is less than 0.1 part by weight, there is a possibility that the electrolyte and the solvent do not sufficiently contact each other, and if the amount is more than 1000 parts by weight, the improvement in the cleaning effect is slight.

What is necessary is just to set the quantity of a 2nd poor solvent suitably, and specifically 0.1 weight part or more is preferable with respect to 1 weight part of preparation amounts of a polymer, and 1 weight part or more is more preferable. Moreover, 1000 weight part or less is preferable, 500 weight part or less is more preferable, and 100 weight part or less is further more preferable. If the amount is less than 0.1 part by weight, there is a possibility that the electrolyte and the solvent do not sufficiently contact each other, and if the amount is more than 1000 parts by weight, the improvement in the cleaning effect is slight.

The washing conditions for the polymer electrolyte are not particularly limited as long as the impurity concentration in the polymer electrolyte can be efficiently lowered. Specifically, it is preferably 0 ° C. to 150 ° C., more preferably 30 ° C. to 100 ° C. In addition, it is preferably stirred for 10 minutes to 10 hours, more preferably 30 minutes to 2 hours per washing solvent. When the temperature is lower than 0 ° C, a sufficient cleaning effect may not be obtained. When the temperature is higher than 150 ° C, a side reaction may occur. Further, if it is shorter than 10 minutes, sufficient cleaning efficiency may not be obtained, and even if it is longer than 10 hours, the cleaning effect is weak.

The polymer electrolyte may be in any shape as long as it has a high cleaning effect and a large surface area, and may be in the form of a fiber or powder. Preferably, it is a powder with a larger surface area.

The polymer electrolyte before washing contains a compound having a molecular weight of 10,000 or less as an impurity exhibiting a deterioration effect on the catalyst and electrode of the fuel cell. Examples of such compounds include ligands and central metals derived from transition metal complexes used in the polymerization, molecules formed by the reaction of the ligand in the post-polymerization process, and oligomers used in the manufacturing process. Examples include adducts in which an acid reacts with a ligand. In addition, oligomer components that are not contained in a high molecular weight material such as a raw material compound of a polymer electrolyte or an oligomer generated from the compound at the time of polymerization are also included. Also, hydrophilic oligomers may flow out during use as a fuel cell, and it is preferable to remove them beforehand because there is a concern about the influence of sulfate ions on the catalyst and electrodes. As is well known, the metal element may be mixed from the manufacturing process and raw materials in addition to the central metal used in the reaction, and examples thereof include iron, nickel, chromium, zinc, and copper. Examples of the halogen element include those released from a monomer or oligomer as a leaving group during polymerization, chlorine ions as the residue of hydrochloric acid used in the acid washing step, bromine ions mixed in the manufacturing step, and the like.

The impurities include oligomers having a number average molecular weight of 10,000 or less. Examples of the oligomer include an oligomer formed by self-condensation of a metal complex ligand (for example, a compound having an unsaturated bond), a halide thereof, a raw material oligomer of a polymer electrolyte, an oligomer generated from the raw material oligomer during polymerization, and the like. Is mentioned.
In particular, hydrocarbon compounds containing unsaturated bonds (for example, oligomers formed from 1,5-cyclooctadiene, which is a ligand of metal complexes), and those in which the hydrocarbon compounds are substituted with halogen elements are removed. It is preferable to keep it.

（式中、Ａｒはベンゼン環、ナフタレン環、またはそれらの環を形成する炭素がヘテロ原子へと置換されたものを示し、Ｘは水素または陽イオンを示す。ａおよびｂは、それぞれ０〜４の整数である。また、ａ＋ｂは１以上である。ｍは１以上の整数を示し、ｎは０以上の整数を示す。） (2. Polymer electrolyte)
As the polymer electrolyte used in the present invention, the following formula (1):

(In the formula, Ar represents a benzene ring, a naphthalene ring, or a carbon in which those rings are substituted with a hetero atom, X represents hydrogen or a cation. In addition, a + b is 1 or more, m is an integer of 1 or more, and n is an integer of 0 or more.)

It is preferable to have a structure represented by Here, as a cation, a Group 1 metal ion such as lithium, sodium or potassium, a Group 2 metal ion such as magnesium or calcium, a Group 13 metal ion such as aluminum, or a Group 3 to 12 group ion. Examples thereof include metal ions of transition metals. Further, n / (m + n) is preferably 0 to 0.95, and more preferably 0.30 to 0.90.

In the polymer electrolyte used in the present invention, the total content of the structure represented by the formula (1) is preferably 20% by weight or more, and more preferably 30% by weight or more. The upper limit is not particularly limited. If it is less than 20% by weight, it may not have sufficient proton conductivity. Here, the total weight of the polymer electrolyte is the dry weight of the polymer electrolyte after the polymer electrolyte is treated with an acid and the sulfonic acid group in the polymer is in the SO ₃ H state. When there are some components having a sulfonic acid group, the component ratio can be determined from an analytical method such as a ¹ H-NMR spectrum.

（式中、Ｘ、ａ、ｂ、ｍ、ｎは前記式（１）と同様である。）
で示される構造であることが好ましい。 The structure represented by the formula (1) is based on the following formula (4), in which Ar is a benzene ring in terms of easy availability of raw materials:

(In the formula, X, a, b, m and n are the same as those in the formula (1).)
It is preferable that it is a structure shown by these.

（式中、Ａｒ、ｍ、ｎは前記式（１）と同様である。Ｙ^１はＳＯ_２、Ｃ（ＣＨ_３）_２、またはＣ（ＣＦ_３）_２であり、Ｚは直接結合、酸素、または硫黄を示す。）および／または下記式（３） As the polymer electrolyte used in the present invention, the following formula (2)

(In the formula, Ar, m, and n are the same as those in the above formula (1). Y ¹ is SO ₂ , C (CH ₃ ) ₂ , or C (CF ₃ ) ₂ , Z is a direct bond, oxygen, Or represents sulfur) and / or the following formula (3):

（式中、Ａｒ、ｍ、ｎは前記式（１）と同様である。Ｙ^２はＣＯ、ＳＯ_２、Ｃ（ＣＨ_３）_２、またはＣ（ＣＦ_３）_２であり、Ｙ^１とは異なる。Ｚは直接結合、酸素、または硫黄を示す。）
で示される構造を主鎖に有することが好ましい。また、式（２）で示される構造成分Ａモルに対し、式（３）で示される構造成分Ｂモルが、Ｂ／（Ａ＋Ｂ）が０〜０．９５を満たすことが好ましく、０〜０．６０であることがより好ましい。また、ｎ／（ｍ＋ｎ）は、０〜０．９５が好ましく、０．３０〜０．９０であることがより好ましい。

(In the formula, Ar, m, and n are the same as those in the formula (1). Y ² is CO, SO ₂ , C (CH ₃ ) ₂ , or C (CF ₃ ) ₂ , and is different from Y ^1. Z represents a direct bond, oxygen or sulfur.)
It is preferable to have a structure represented by Moreover, it is preferable that B / (A + B) satisfy | fills 0-0.95 with respect to the structural component A mol shown by Formula (2), B / (A + B) shown by Formula (3). 60 is more preferable. Further, n / (m + n) is preferably 0 to 0.95, and more preferably 0.30 to 0.90.

The total content of the structures represented by the formulas (2) and (3) is preferably 20% by weight or more, and more preferably 30% by weight or more. Further, it is preferably 95% by weight or less, more preferably 90% by weight or less, further preferably 80% by weight or less, and particularly preferably 70% by weight or less. When the amount is less than 20% by weight, the water resistance tends to decrease, and when the amount exceeds 95% by weight, the conduction performance tends to decrease.

（式中、Ｙ^１、Ｚは前記式（２）と同様である。）
および下記式（６）

（式中、Ｙ^２、Ｚは前記式（３）と同様である。）
で示される構造であることが好ましい。 In the structures represented by the formulas (2) and (3), Ar is a benzene ring and m and n are both 1 in terms of easy availability of raw materials.

(Wherein Y ¹ and Z are the same as those in the formula (2)).
And the following formula (6)

(In the formula, Y ² and Z are the same as those in the formula (3).)
It is preferable that it is a structure shown by these.

（式中、Ａｒ、Ｘ、ａ、ｂ、ｍ、ｎは、前記式（１）と同様であり、Ｚは前記式（２）と同様である。Ｗは直接結合、ＣＯ、ＳＯ_２、Ｃ（ＣＨ_３）_２、またはＣ（ＣＦ_３）_２である。）
で示される構造を主鎖に含んでもよい。また、ｎ／（ｍ＋ｎ）は、０〜０．９５が好ましい。 As the polymer electrolyte used in the present invention, the following formula (7) having a structure different from the formula (1) from the viewpoint of ease of workability.

(In the formula, Ar, X, a, b, m, and n are the same as in the above formula (1), and Z is the same as in the above formula (2). W is a direct bond, CO, SO ₂ , C (CH ₃ ) ₂ or C (CF ₃ ) ₂
The structure represented by may be included in the main chain. Further, n / (m + n) is preferably 0 to 0.95.

When the structure represented by the formula (7) is included, the total content of the structure represented by the formula (1) and the structure represented by the formula (7) is preferably 5% by weight or more based on the total weight. % Or more is more preferable. The upper limit is not particularly limited, but is preferably 80% by weight or less, and more preferably 70% by weight or less. If it exceeds 80% by weight, the resistance to dissolution in water decreases, and if it is less than 5% by weight, the workability tends to decrease.

The polymer electrolyte used in the present invention may be a random copolymer, a graft copolymer or a block copolymer as long as it has the above structure in the main chain. Under low humidification conditions, the water inside the polymer electrolyte membrane is reduced, but in order to enhance proton conduction, it is necessary to effectively use water as a proton conducting medium, and for that purpose, a micro phase separation structure is formed, More preferably, it is a block copolymer capable of producing a water-rich phase.

Furthermore, in the block copolymer that forms a microphase separation structure, it is possible to collect more water in the hydrophilic phase by separating the hydrophilic phase and the hydrophobic phase. It is preferably a block copolymer comprising a hydrophilic segment having a group and a hydrophobic segment not having a sulfonic acid group.

（式中、Ａｒ、Ｘ、ｍは前記式（１）と同様である。）
で示される構造を有することが好ましい。 The hydrophilic segment having a sulfonic acid group preferably has a structure represented by the above formula (1). In the formula (1), a, b and n are 1, and the following formula (8)

(In the formula, Ar, X and m are the same as those in the formula (1).)
It is preferable to have the structure shown by these.

Moreover, it is preferable that 20 weight% or more of the weight of the whole polymer electrolyte is a structure shown by said Formula (1), and it is more preferable that it is 30 weight% or more. The upper limit is not particularly limited. If it is less than 20% by weight, the resistance to dissolution in water tends to decrease.

（式中、Ａｒ、ｍ、ｎは前記式（１）と同様である。Ｙ^１はＳＯ_２、Ｃ（ＣＨ_３）_２、またはＣ（ＣＦ_３）_２であり、Ｚは直接結合、酸素、または硫黄を示す。）および／または下記式（３） The hydrophobic segment having no sulfonic acid group preferably has a structure in which a high molecular weight polymer can be easily obtained.

(In the formula, Ar, m, and n are the same as those in the above formula (1). Y ¹ is SO ₂ , C (CH ₃ ) ₂ , or C (CF ₃ ) ₂ , Z is a direct bond, oxygen, Or represents sulfur) and / or the following formula (3):

（式中、Ａｒ、ｍ、ｎは前記式（１）と同様である。Ｙ^２はＣＯ、ＳＯ_２、Ｃ（ＣＨ_３）_２、またはＣ（ＣＦ_３）_２であり、Ｙ^１とは異なる。Ｚは直接結合、酸素、または硫黄を示す。）
で示される構造を含むものが、有機溶媒への溶解性が良好で高分子量ポリマーを得やすいため好ましい。

(In the formula, Ar, m, and n are the same as those in the formula (1). Y ² is CO, SO ₂ , C (CH ₃ ) ₂ , or C (CF ₃ ) ₂ , and is different from Y ^1. Z represents a direct bond, oxygen or sulfur.)
Those having a structure represented by the formula (1) are preferred because they have good solubility in organic solvents and are easy to obtain high molecular weight polymers.

The total content of the structures represented by the formulas (2) and (3) is preferably 20% by weight or more, and more preferably 30% by weight or more. Further, it is preferably 95% by weight or less, more preferably 90% by weight or less, further preferably 80% by weight or less, and particularly preferably 70% by weight or less. When the amount is less than 20% by weight, the water resistance tends to decrease, and when the amount exceeds 95% by weight, the conduction performance tends to decrease.

The polymer electrolyte used in the present invention preferably has an ion exchange capacity of 1.0 to 4.0 meq / g, more preferably 1.2 to 3.8 meq / g, What is 1.4-3.6 meq / g is more preferable.

Further, when the polymer electrolyte used in the present invention is a graft copolymer or a block copolymer, the ion exchange capacity of the hydrophilic segment is 1.0 to 6.5 meq / g from the viewpoint of proton conductivity. Is preferably 5.3 to 6.0 meq / g, and more preferably 5.8 to 6.0 meq / g.

（式中、Ｘは水素か陽イオンである。Ｙは２価の電子求引性基を示し、例えばＣＯ、ＳＯ_２、あるいはＣ（ＣＦ_３）_２などである。）
で示される構造であり、さらに好ましくは下記式 Moreover, as a polymer electrolyte used by this invention, it is preferable that a part or all sulfonic acid group exists on the aromatic ring which has an electron withdrawing group. More preferably, the following formula

(In the formula, X represents hydrogen or a cation. Y represents a divalent electron-withdrawing group such as CO, SO ₂ , or C (CF ₃ ) _2. )
And more preferably the following formula:

（式中、Ｘは水素か陽イオンである。Ｙは２価の電子求引性基を示し、例えばＣＯ、ＳＯ_２、あるいはＣ（ＣＦ_３）_２などである。）
で示される構造であり、もっとも好ましくは下記式

(In the formula, X represents hydrogen or a cation. Y represents a divalent electron-withdrawing group such as CO, SO ₂ , or C (CF ₃ ) _2. )
And most preferably the following formula:

（式中、Ｘは水素か陽イオンである。Ｙは２価の電子求引性基を示し、例えばＣＯ、ＳＯ_２、あるいはＣ（ＣＦ_３）_２などである。）
で示される構造である。

(In the formula, X represents hydrogen or a cation. Y represents a divalent electron-withdrawing group such as CO, SO ₂ , or C (CF ₃ ) _2. )
It is a structure shown by.

Regarding the weight ratio contained in the polymer electrolyte, the weight ratio between the component having a sulfonic acid group and the component having no sulfonic acid group can be determined from the ion exchange capacity of the polymer electrolyte.

(3. Preparation of polymer electrolyte)
The polymer electrolyte used in the present invention may be prepared by applying a general polymerization reaction ("Experimental Chemistry Course 4th Edition Organic Synthesis VII Synthesis Using Organometallic Reagents" P353-366 (1991) Maruzen Co., Ltd.). it can.

As the material used for the polymerization, a compound having two or more leaving groups can be used, and a compound having a leaving group such as a halogen group or a sulfonate group can be used. From the viewpoint of availability of materials and reactivity, a compound having halogen groups such as chlorine, bromine and iodine as two leaving groups is preferable.

The molecular weight of the material is preferably 50 to 1,000,000, and the molecular weight of the material forming a hydrophilic segment having a sulfonic acid group is particularly preferably 100 to 50,000, and the material forming a hydrophobic segment having no sulfonic acid group The molecular weight of is preferably 1000 to 100,000. The molecular weight of the polymer electrolyte synthesized by these materials is preferably 10,000 to 5,000,000, and more preferably 20,000 to 1,000,000, both workability for producing the polymer electrolyte membrane and the strength of the polymer electrolyte membrane are excellent. Therefore, it is preferable.

The polymerization reaction can be carried out in a nitrogen gas atmosphere or an argon gas atmosphere as long as it is in an inert gas atmosphere.

When carrying out a polymerization reaction between materials having a leaving group such as a halogen group at the terminal, it is preferably carried out in the presence of a zero-valent transition metal complex. The zero-valent transition metal complex is a transition metal in which a halogen element or a ligand is coordinated, and either a commercially available product or one prepared separately from a polyvalent metal complex can be used.

The preparation method of the zero-valent transition metal complex includes, for example, a method of reacting a transition metal salt or transition metal oxide with a ligand, a method of making a transition metal compound zero-valent with a reducing agent such as zinc or magnesium, etc. A well-known method is mentioned. The prepared zero-valent transition metal complex may be used after being taken out from the prepared system, or may be used in situ as it is.

Examples of the zero-valent transition metal complex include a zero-valent nickel complex, a zero-valent palladium complex, a zero-valent platinum complex, and a zero-valent copper complex. Among these transition metal complexes, a zero-valent nickel complex and a zero-valent palladium complex are preferably used, and a zero-valent nickel complex is more preferably used. Specifically, bis (1,5-cyclooctadiene) nickel (0), (ethylene) bis (triphenylphosphine) nickel (0), tetrakis (triphenylphosphine) nickel, tetrakis (triphenylphosphine) palladium ( 0). Among these, bis (1,5-cyclooctadiene) nickel (0) is preferable from the viewpoint of reactivity, yield of the obtained polymer and the like, and increase in the molecular weight of the obtained polymer and the like.

In the condensation reaction using a zero-valent transition metal complex, it is preferable to add a compound capable of forming a complex with the zero-valent transition metal as a ligand to the reaction system from the viewpoint of improving the yield of the resulting polymer. The compound to be added may be the same as or different from the ligand of the zero-valent transition metal complex used. Specifically, triphenylphosphine and 2,2'-bipyridyl are preferable from the viewpoints of versatility, economy, reactivity, yield of the obtained polymer and the like and high molecular weight of the obtained polymer. In particular, it is preferable to use 2,2'-bipyridyl in terms of improving the polymer yield and increasing the molecular weight. The addition amount of the ligand is preferably about 0.2 to 10 mol times, more preferably about 1 to 5 mol times based on the transition metal atom in the zero-valent transition metal complex.

The amount of the zero-valent transition metal complex used is preferably 0.1 mol times or more with respect to the total molar amount of the compound having a leaving group such as a monomer used for polymerization. If the amount used is too small, the molecular weight of the resulting polymer tends to be small, more preferably 1.5 mole times or more, still more preferably 1.8 mole times or more, even more preferably 2.1 mole times or more. Use. On the other hand, the upper limit of the amount used is not particularly limited, but if the amount used is too large, the removal process of low molecular weight impurities derived from the ligand becomes complicated, and if these are mixed inside the polymer electrolyte, the voltage drops. Therefore, it is preferably 5.0 mole times or less.

The solvent in the polymerization reaction is not particularly limited as long as polymerization is not prohibited, and carbonate compounds (ethylene carbonate, propylene carbonate, etc.), heterocyclic compounds (3-methyl-2-oxazolidinone, 1-methyl-2-pyrrolidone) (Hereinafter referred to as NMP), N, N-dimethylimidazolidinone (hereinafter referred to as DMI), cyclic ethers (dioxane, tetrahydrofuran, etc.), chain ethers (diethyl ether, ethylene glycol dialkyl ether, etc.), nitrile compounds (acetonitrile, Glutaronitrile, methoxyacetonitrile, etc.), aprotic polar substances (N, N-dimethylacetamide (hereinafter DMAc), N, N-dimethylformamide (hereinafter DMF), dimethyl sulfoxide (hereinafter DMSO), sulfolane, etc.), nonpolar solubility (Toluene, xylene), etc. can be enumerated, among others DMAc or DMF from solubility, NMP, DMI, DMSO and the like is preferable because of high solubility in the polymer. Among these, DMAc and DMSO are more preferable because of their high solubility, and these may be used alone or in combination of two or more. In addition, in order to remove a small amount of water in the solvent, it is effective to add azeotropic solvent such as benzene, toluene, xylene, cyclohexane and remove water by azeotropic distillation.

What is necessary is just to set the reaction temperature of a superposition | polymerization process suitably. Specifically, 0-200 degreeC is preferable, More preferably, it is 20-170 degreeC, More preferably, it is 40-140 degreeC. If the temperature is lower than 0 ° C., the reaction rate is slow, and if the temperature is higher than 200 ° C., the reaction is greatly affected by a small amount of impurities and coloring of the polymer or side reaction may occur.

When the polymer electrolyte is synthesized as a block copolymer, a compound having two or more leaving groups can be used as a material for forming a hydrophilic segment having a sulfonic acid group. Examples of the leaving group include a halogen group and a sulfonate group. A compound having a leaving group on the aromatic ring is preferable, and a dichlorobenzene derivative, a dichlorobenzophenone derivative, and a dichlorophenylsulfone derivative are more preferable in view of availability of materials.

As a material for forming a hydrophobic segment having no sulfonic acid group, a compound having two or more leaving groups can be used. Examples of the leaving group include a halogen group and a sulfonate group. Preferably, a compound having a leaving group on an aromatic ring is preferred. From the viewpoint of easy availability of the material, a dichlorobenzene derivative, a dichlorobenzophenone derivative, a dichlorophenylsulfone derivative, or at least these are synthesized as raw materials, and two or more leaving groups are provided. More preferred is a polymer. When the material forming the hydrophobic segment is a polymer, the molecular weight is preferably 1000 to 100,000.

When synthesizing a polyelectrolyte as in the present invention, the rigidity is lowered by protecting part or all of the carbonyl groups contained in the hydrophilic segment and the hydrophobic segment material, and a higher molecular weight polymer is obtained. be able to.

The protection of the carbonyl group is a method generally performed in organic synthesis, and is to temporarily convert into a functional group having different properties when the carbonyl group works adversely in the process of synthesis. Usually, a carbonyl group protected can be converted to a carbonyl group by deprotection.

For protecting the carbonyl group, for example, as a general method (“Protective Groups in Organic Synthesis Edition”, p. 293-368 (1999) John Wiley & Sons, Theodora W. Greene) can be applied. it can. Protection can take place at any of the monomer, oligomer and polymer stages.

A specific example of the protection of the carbonyl group is a method of converting the carbonyl group into an acetal or ketal by reacting the carbonyl group with an alcohol. For example, the method of Unexamined-Japanese-Patent No. 2007-59374 etc. are mentioned. Another example is a method in which a carbonyl group is reacted with an amine to convert it to an imine or ketimine. Examples thereof include the method described in “Macromolecules 1994, 27, 2354-2356”. In any case, as a deprotection method, the method described in the cited literature can be used. Acetals, ketals, imines and ketimines mentioned here are hydrolyzable and can be deprotected in a solvent containing water. In general, it is carried out under acidic conditions in order to accelerate deprotection.

Specifically, there is a method in which the carbonyl group of the formula (1) is protected and converted to CR ¹ R ² or C═NR ³ . R ¹ and R ² represent an alkoxy group or an aryloxy group, and CR ¹ R ² may have a cyclic structure. R3 represents an alkyl group or an aryl group.

In the case of deprotection, it can be easily deprotected by contact with water or an acidic aqueous solution. Further, the deprotection is preferably performed in the form of a film from the viewpoint of ease of processing. The carbonyl group may be protected at any stage of monomer, oligomer, or polymer, but deprotection is preferably performed at the polymer stage.

As a treatment after the polymerization step, the polymer electrolyte is washed with an acid as necessary. The acid used here may be any acid that can protonate the end of the polymer. For example, as the inorganic acid, sulfuric acid, nitric acid, hydrochloric acid, hydrogen bromide, hydrogen iodide, hypochlorous acid, chlorous acid, chlorine Examples include acids, perchloric acid, phosphoric acid, and fluorosulfonic acid. Examples of organic acids include acetic acid, formic acid, toluenesulfonic acid, methanesulfonic acid, and the like.

What is necessary is just to set the density | concentration of the acid to be used suitably according to reaction, and 0.1-20N is specifically preferable. More preferably, it is 0.5-15N, More preferably, it is 1-12N. If it is thinner than 0.1N, the purification effect becomes insufficient, and if it is thicker than 20N, the subsequent cleaning becomes complicated.

What is necessary is just to set the quantity of the acid used for washing | cleaning suitably, specifically 0.1-1000 weight part is preferable with respect to 1 weight part of preparation amounts of a polymer, More preferably, it is 1-500 weight part, Preferably it is 1-100 weight part. If the amount is less than 0.1 parts by weight, there is a possibility that the precipitated solid does not sufficiently come into contact with the acid. If the amount is more than 1000 parts by weight, removal of the acid in the water washing step may be complicated.

The polymer electrolyte membrane obtained by the production method of the present invention can be used in various industries, and its use (use) is not particularly limited, but the polymer electrolyte membrane, the membrane / electrode assembly Suitable for fuel cells.

(4. Fuel cell electrolyte membrane)
An electrolyte membrane for a fuel cell can be prepared using the polymer electrolyte obtained by the production method of the present invention. This polymer electrolyte membrane is obtained by processing the above-described polymer electrolyte into a membrane shape (film shape). As such a film forming method, a known method is appropriately applied. Examples of the known methods include film forming methods from solutions such as hot extrusion methods, inflation methods, melt extrusion molding such as T-die methods, casting methods, and emulsion methods. For example, a casting method is exemplified as a method for forming a film from a solution. This is a method in which a polymer electrolyte solution with adjusted viscosity is applied onto a flat plate such as a glass plate using a bar coater, a blade coater, or the like, and a solvent is vaporized to obtain a film. Industrially, it is also common to apply a solution continuously from a coating die onto a belt and vaporize the solvent to obtain a long product.

Furthermore, in order to control the molecular orientation of the polymer electrolyte, the obtained polymer electrolyte membrane may be subjected to a treatment such as biaxial stretching or a heat treatment for controlling the crystallinity. . Further, various fillers may be added to improve the mechanical strength of the polymer electrolyte membrane, or a reinforcing agent such as a glass cloth may be combined with the polymer electrolyte by pressing.

As the thickness of the polymer electrolyte membrane, any thickness can be selected according to the application. For example, when considering reducing the internal resistance of the obtained polymer electrolyte membrane, the thinner the polymer electrolyte membrane, the better. On the other hand, in consideration of gas barrier properties and handling properties of the obtained polymer electrolyte membrane, it may not be preferable if the thickness of the polymer electrolyte membrane is too thin. Considering these, the thickness of the polymer electrolyte membrane is preferably 1.2 μm or more and 350 μm or less. If it is in this range, handling will be improved, such as easy handling and less damage. In addition, the proton conductivity of the obtained polymer electrolyte membrane can be expressed within a desired range.

In order to further improve the properties of the polymer electrolyte membrane, it is possible to irradiate radiation such as electron beam, γ-ray, ion beam and the like. By these, a crosslinked structure etc. can be introduce | transduced in a polymer electrolyte, and a performance may improve further. In addition, various surface treatments such as plasma treatment and corona treatment can improve properties such as improving adhesion to the catalyst layer on the surface of the polymer electrolyte membrane.

Hereinafter, the present invention will be described in more detail.
A method for measuring the molecular weight, metal residual amount, and ion residual amount of the prepared polymer electrolyte is shown below.

<Measurement of molecular weight>
The molecular weights of the prepared oligomers and polymer electrolytes were measured by the GPC method and calculated from converted values using standard polystyrene samples.
GPC measuring device HLC-8220 manufactured by Tosoh Corporation
Column Showa Denko Super AW 4000, Super AW 2500 connected in series Column temperature 40 ° C
Mobile phase NMP (LiBr 10 mmol / dm ³ )
Flow rate 0.3mL / min
Detector RI detector

<Measurement of metal content by ICP-MS method>
As a pretreatment, the sample was weighed, sulfuric acid and nitric acid were added, and pressure acid decomposition was performed using a microwave decomposition apparatus. A constant volume of 25 mL of the decomposition solution was measured and analyzed by ICP-MS method.
Equipment Agilent 7500CX made by Agilent Technologies

<Chlorine concentration analysis by ion chromatography>
Pretreatment method Combustion tube combustion method pretreatment device AQF-2100H manufactured by Mitsubishi Chemical Analytech Co., Ltd.
IC measurement device ICS-2000 made by Nippon Dionex
Column IonPac AG18, AS18
Eluent KOH gradient flow rate 1.0mL / min
Detector Electrical conductivity detector

<Manufacture of membrane electrode assembly>
The membrane / electrode assembly necessary for measuring the power generation performance of the electrolyte membrane in the present invention was produced by the following procedure using a heating and pressure welding machine (manufactured by Tester Sangyo Co., Ltd.).
First, a SUS plate, a polytetrafluoroethylene (PTFE) sheet (100 mm × 100 mm × 0.3 mm), an anode side gas diffusion electrode (22 mm × 22 mm), and a PTFE sheet (100 mm × 100 mm × 0) cut out from the gas diffusion electrode portion. .2 mm), polymer electrolyte membrane (Examples and Comparative Examples), PTFE sheet (100 mm × 100 mm × 0.2 mm) cut out from the catalyst layer, cathode side gas diffusion electrode (22 mm × 22 mm), PTFE sheet (100 mm × 100 mm × 0.3 mm) and SUS plates were laminated in this order. After this laminate was placed on a pressure plate heated to 150 ° C., it was produced by heating and pressing under conditions of holding at 50 kgf / cm ² for 5 minutes.
<PEFC power generation characteristics evaluation>
A single fuel cell was assembled using the membrane electrode assembly. First, an anode side end plate, a gas flow plate, a PTFE gasket (0.20 mm), a membrane electrode assembly, a PTFE gasket (0.20 mm), a gas flow plate, and an end plate were laminated in this order. Next, the fuel cell single cell was produced by tightening at 2 Nm using the M3 bolt. Subsequently, after the single cell was installed in an evaluation apparatus equipped with an electronic load device (PLZ164WA, manufactured by Kikusui Electronics Co., Ltd.), fuel (hydrogen, 84 ml / min, 100% RH) was anodeed at a cell temperature of 80 ° C. Supplied to the side. Further, an oxidizing agent (air, 400 ml / min, 100% RH) was supplied to the cathode side. Next, the electronic load device was set to a constant current mode, and the fuel cell including the membrane electrode assembly was held at a voltage of 0.5 V for 24 hours to condition the PEFC. Finally, at a cell temperature of 80 ° C., fuel (hydrogen, 83 ml / min, 53% RH) is supplied to the anode side, and oxidant (air, 272 ml / min, 53% RH) is supplied to the cathode side. The power generation characteristics at ^{2 A} / cm ² were evaluated.

(Synthesis Example 1)
50.2 g of 4,4′-dichlorobenzophenone and 270 g of 30% fuming sulfuric acid were mixed and reacted at 130 ° C. for 6 hours. After completion of the reaction, the temperature was returned to room temperature and poured into NaCl water (500 ml). The precipitated solid was collected by filtration, added to water (500 ml), and neutralized with NaOH. The solid in the system was collected by filtration and then dried under reduced pressure to obtain 81.1 g (yield 89%) of the desired product as a white solid.

(Synthesis Example 2)
A three-necked flask equipped with a Liebig condenser, Dean-Stark, mechanical stirrer and purged with nitrogen was charged with 4,4′-dichlorodiphenylsulfone (31.6 g) and 4,4′-dihydroxybenzophenone (21.42 g), Potassium carbonate (20.78 g), DMAc (200 ml) and toluene (50 ml) were added. This solution was stirred for 3 hours under an oil bath heating condition of 140 ° C., then heated to 170 ° C., further stirred for 24 hours, and then cooled to room temperature. The reaction solution was dropped into methanol, and the resulting white precipitate was collected by filtration. The solid was put into water and the aqueous phase was neutralized, followed by stirring at 60 ° C. for 1 hour. After filtration, it was washed again with water at 60 ° C., and further washed with methanol at 60 ° C. The solid obtained by filtration was vacuum-dried at 70 ° C. to obtain the target oligomer as a white solid.

(Synthesis Example 3)
A three-necked flask equipped with a Liebig condenser, a Dean-Stark pipe and a mechanical stirrer and purged with nitrogen was added to 12 g of the sulfonated monomer obtained in Synthesis Example 1, 8 g of the oligomer obtained in Synthesis Example 2, and 2,2′-bipyridine 11. .56 g, DMSO 240 ml and toluene 60 ml were added. This was refluxed under an oil bath heating condition of 170 ° C. to remove moisture in the system, and then toluene was removed to cool to 60 ° C. To this was added 20 g of bis (1,5-cyclooctadiene) nickel, and then reacted at 80 ° C. for 3 hours to obtain a polymerization solution.

Example 1
After completion of the reaction of Synthesis Example 3, the polymerization solution was poured into 1000 ml of methanol to precipitate a solid. After stirring at room temperature for 1 hour, the solid was collected by filtration. The obtained solid was acid-treated with 800 ml of concentrated hydrochloric acid, then washed with water until the washing solution became neutral, and dried under reduced pressure at 105 ° C. to obtain 15.1 g of the target polymer electrolyte. The molecular weight of this polymer electrolyte was Mn = 12,000 and Mw / Mn = 2.77.

After the obtained electrolyte was finely pulverized, 135 ml of dichloromethane was used as the first poor solvent, and the mixture was stirred for 1 hour under heating and refluxing conditions, and then the solid was collected by filtration. Next, 100 ml of methanol was used as the second poor solvent and stirred at room temperature for 1 hour. The polymer electrolyte after washing was dried under reduced pressure under heating at 70 ° C. to obtain a purified solid.

After 0.7 g of the obtained polymer electrolyte was dissolved in 20 ml of DMSO, the solution was cast on a glass substrate, dried under reduced pressure at 80 ° C. for 15 hours, and further dried under reduced pressure at 100 ° C. for 18 hours. This was repeated with washing with 6N hydrochloric acid at room temperature for 3 hours for 3 hours, then with washing with water for 1 hour twice, and dried with a dryer at 60 ° C. to obtain a polymer electrolyte membrane.

(Example 2)
After completion of the reaction in Synthesis Example 3, the polymerization solution was poured into 1000 ml of isopropyl alcohol to precipitate a solid. After stirring at room temperature for 1 hour, the solid was collected by filtration. The obtained solid was acid-treated with 800 ml of concentrated hydrochloric acid, then washed with water until the washing solution became neutral, and dried under reduced pressure at 105 ° C. to obtain 15 g of the target polymer electrolyte. The molecular weight of this polymer electrolyte was Mn = 109,000 and Mw / Mn = 2.32.

After the obtained electrolyte was finely pulverized, 135 ml of dichloromethane was used as the first poor solvent, and the mixture was stirred for 1 hour under heating and refluxing conditions, and then the solid was collected by filtration. Next, 100 ml of methanol was used as the second poor solvent and stirred at room temperature for 1 hour. The polymer electrolyte after washing was dried under reduced pressure under heating at 70 ° C. to obtain a purified solid.
The obtained polymer electrolyte was used as a polymer electrolyte membrane in the same manner as in Example 1, and various evaluations were performed.

(Example 3)
After completion of the reaction in Synthesis Example 3, the polymerization solution was poured into 600 ml of concentrated hydrochloric acid to precipitate a solid. After stirring at room temperature, the solid was filtered. The solid was washed with water until the washing solution became neutral and dried under reduced pressure at 105 ° C. to obtain 14.8 g of the target polymer electrolyte. The molecular weight of this polymer electrolyte was Mn = 53,000 and Mw / Mn = 4.61.

After the obtained electrolyte was finely pulverized, 135 ml of dichloromethane was used as the first poor solvent, and the mixture was stirred for 1 hour under heating and refluxing conditions, and then the solid was collected by filtration. Next, 100 ml of methanol was used as the second poor solvent and stirred at room temperature for 1 hour. The polymer electrolyte after washing was dried under reduced pressure under a heating condition of 70 ° C. to obtain a purified solid.
The obtained polymer electrolyte was used as a polymer electrolyte membrane in the same manner as in Example 1, and various evaluations were performed.

(Comparative Example 1)
After completion of the reaction in Synthesis Example 3, the polymerization solution was poured into 600 ml of concentrated hydrochloric acid to precipitate a solid. After stirring at room temperature for 1 hour, the solid was filtered, washed with water, and dried under reduced pressure at 105 ° C. to obtain the target polymer electrolyte. The molecular weight of this polymer electrolyte was Mn = 105,000 and Mw / Mn = 2.34.
The obtained polymer electrolyte was used as a polymer electrolyte membrane in the same manner as in Example 1, and various evaluations were performed.

(Comparative Example 2)
After completion of the reaction of Synthesis Example 3, the polymerization solution was poured into 1000 ml of 6N sulfuric acid to precipitate a solid. After stirring at room temperature for 30 minutes, the solid was filtered, washed with water, and dried under reduced pressure at 105 ° C. to obtain the target polymer electrolyte. The molecular weight of this polymer electrolyte was Mn = 113,000 and Mw / Mn = 2.17.
The obtained polymer electrolyte was used as a polymer electrolyte membrane in the same manner as in Example 1, and various evaluations were performed.

(Comparative Example 3)
A part of the polymer electrolyte after washing with dichloromethane in Example 1 was extracted and dried under reduced pressure under heating at 70 ° C. to obtain a solid.
The obtained polymer electrolyte was used as a polymer electrolyte membrane in the same manner as in Example 1, and various evaluations were performed.

The results of quantifying the amount of impurities remaining in the polymer electrolyte membranes obtained from the examples and comparative examples are shown in Table 1, and the voltage maintenance rate after 900 hours in the power generation test is shown in FIG.
The component content with a molecular weight of 10,000 or less in the text is a value obtained by estimating the abundance ratio of molecules having a molecular weight of 10,000 or less from a molecular weight distribution curve obtained by measurement under the above GPC analysis conditions. The voltage maintenance rate is a voltage (initial voltage) at 0.2 A / cm ² immediately after the start of the power generation characteristic evaluation test, and the value obtained by dividing the voltage when the test under the same condition is continued for 900 hours is expressed as a percentage. Value.

As a result, it has been shown that a film from which impurities having a molecular weight of 10,000 or less, which are deterioration factors of fuel cell catalysts and electrodes, are removed can suppress voltage deterioration.

Claims (5)

A block copolymer comprising a hydrophilic segment having a sulfonic acid group and a hydrophobic segment having no sulfonic acid group, and comprising a solid polymer electrolyte containing an oligomer having a number average molecular weight of 10,000 or less, at least two kinds of high polymer electrolytes A method for producing a polymer electrolyte, comprising a step of washing using a poor solvent for a molecular electrolyte,
As the poor solvent, an alcohol solvent and an aprotic solvent are used ,
The polymer electrolyte is at least the following formula (1)

(In the formula, Ar represents a benzene ring, a naphthalene ring, or a carbon in which those rings are substituted with a hetero atom, X represents hydrogen or a cation. In addition, a + b is 1 or more, m is an integer of 1 or more, and n is an integer of 0 or more.)
The manufacturing method of the polymer electrolyte which has a structure shown by these . A block copolymer comprising a hydrophilic segment having a sulfonic acid group and a hydrophobic segment having no sulfonic acid group, and comprising a solid polymer electrolyte containing an oligomer having a number average molecular weight of 10,000 or less, at least two kinds of high polymer electrolytes A method for producing a polymer electrolyte, comprising a step of washing using a poor solvent for a molecular electrolyte,
As the poor solvent, an alcohol solvent and an aprotic solvent are used,
The polymer electrolyte is represented by the following formula (2)

(In the formula, Ar represents a benzene ring, a naphthalene ring, or a carbon in which those rings are substituted with a hetero atom. M represents an integer of 1 or more, and n represents an integer of 0 or more. Y ¹ is SO ₂ , C (CH ₃ ) ₂ , or C (CF ₃ ) ₂ , Z represents a direct bond, oxygen, or sulfur.) And / or the following formula (3)

(In the formula, Ar, m, and n are the same as those in the formula (2). Y ² is CO, SO ₂ , C (CH ₃ ) ₂ , or C (CF ₃ ) ₂ , and is different from Y ^1. Z represents a direct bond, oxygen or sulfur.)
Has a structure shown in, to structural components A mole of the formula (2), structural component B molar of the formula (3) is, B / (A + B) satisfies 0 to 0.95, high A method for producing a molecular electrolyte. A block copolymer comprising a hydrophilic segment having a sulfonic acid group and a hydrophobic segment having no sulfonic acid group, and comprising a solid polymer electrolyte containing an oligomer having a number average molecular weight of 10,000 or less, at least two kinds of high polymer electrolytes A method for producing a polymer electrolyte, comprising a step of washing using a poor solvent for a molecular electrolyte,
As the poor solvent, an alcohol solvent and an aprotic solvent are used,
The polymer electrolyte has the following formula (7)

(In the formula, Ar represents a benzene ring, a naphthalene ring, or a carbon in which those rings are substituted with a hetero atom, X represents hydrogen or a cation. A + b is 1 or more, m is an integer of 1 or more, n is an integer of 0 or more, Z is a direct bond, oxygen or sulfur, W is a direct bond, CO , SO ₂ , C (CH ₃ ) ₂ , or C (CF ₃ ) _2. )
In comprising the structure shown in the main chain, the method of producing a high molecular electrolyte. The method for producing a polymer electrolyte according to any one of claims 1 to 3 , wherein the aprotic solvent is a halogen-based solvent. The polymer electrolyte production according to any one of claims 1 to 4, wherein the oligomer having a number average molecular weight of 10,000 or less is a hydrocarbon compound substituted with a halogen element and / or a hydrocarbon compound containing an unsaturated bond. Method.

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